Mold for producing crankshafts



Nov. 23, 1948. l. OLSEN MOLD FOR PRODUCING CRANK SHAF'I'S Filed Jan. 12,1945.

5 Sheets-Sheet, 2

Nov. 23, 1948. l. OLSEN 2,454,712

mow FOR rnonucme CRANK SHAF'I'S I Filed Jan. 12, 1945 SShQetS-Sheet sNov. 23, 1948. l, LSEN 2,454,712

MOLD FOR PRODUCING CRANK SHAFTS Filed Jan. 12, 1945 5 Sheets-Sheet 4'Iu/m; 015m By gmufbm NOV 23, 194%. g; o gg MOLD FOR PRODUCING CRANKSHAFTS '5 Shets-Sheei 5 Filed Jan. 12, 1945 amen W041 Patented Nov. 23,1948 UNITED STATES PATENT OFFICE MOLD FOR PRODUCING CRANKSHAFTS- Ivan;Olsen, Muskegon, Mich.

Application January-12, 1945', Serial No. 572,528

1 Claim. 1

My present invention relates; to. improvements in methods of; andapparatuses for producing crank and other similar shafts, andparticularly crank shafts for large: engines, air compressors and pumps;and the objects. of'improvement are: first, to; provide a simple methodor casting heavy crank shafts; second, to providea method ofcastingcrank shafts, whereby the. crank, shaft will have a uniform,structure. throughout; third, to providea method, of casting crankshaftstha wills minimize production. of. faulty castin s;

fourth, to rovide. a. method; of casting. crank shafts; that. will: bereadily: understood; fifth, to provide a method! of casting: crankshaftsthat will; be. easy to practice; sixth, to provide a method oftcastin crank shafts: mass produce 17110112; seventh, to; provide; a,sectional flask and mold. adap able for castin shaf v h v a. pluralityof cranks. or different crank angles; thto providefa consisting of aplurality of; cylindrical sec ions: each havin m d with mold: cavitytherein: in which to: cast a longitudinal: portion of a crank shaftsimultaneously with other portions of the crank shaft.

I attain; these; named objects and: such other objects as appear from aperusal, of the followin description taken with reference to thestructure disclosed by the accompanyin drawing in which: Figure 1 is alongitudinal sidevtiew of a crank shaft casting asproduced by my presentmethod;

Figure 2 an end view of the said crankshaft casting and having crankthrowscircumferentially spaced 1-20 degrees. apart;

Figure 3-- an end viewof the crank shaft. casting having the cranksthereof diagrammatically op,- posi-te each other;

Figure 4, a plan view of the-flask assembly containing the mold in whichthe: crank shaft. is cast y y me o Figure 5 a side elevation view ofthe: flask and mold assembly;

Figure, 6: anend elevation view of the flask mounted for pouring themolten metal therein to form the crank shaft. in the mold in the flaskassembly;

Figure '7 a transverse crossesectional View of the flask and moldtherein taken on line III-III of Figures 4 and- 5-;

Figure 8 a transverse cross-sectional view of the; flask and mold takenon line IV-I-V oi -Eigur s 4 and.

Eligure 9= an end view of one semicylindrical portion of the flask andshaft pattern mounted on the pattern plate in readiness for fillin withmolding sand, the flask being'shown in section;

Figure 10 a top plan view of one of the pattern plates with a section ofthe crank shaft pattern mounted thereon;

Figure 11 one of the semicylindrical flask portions with the moldportion adapted to have cast therein the portion extending between linesI and II of Figure. 1;

Figure 1-2. one of the mold end closing sections.

Throughout the several views of the accompanying drawing similarnumerals refer to similar parts and portions of the flask and the moldemployed in producing cast metal crank shafts by my method, andreferring to the drawing:

Numeral l designates the flask as a: whole, which consists ofcylindrical mold end closing sections 2, semicylindrical flask dragportions 3,, 4, 5-, 6, i, and semicylindrical cope portions 8, 9, Ill, Hand I2; each drag portion 3, 4, 5, 6' and! having an outwardly extendingflange l3 at its rim and engaged by outwardly extending flange H- ofeach of the cope portions, the flanges l3 and 14 being adapted to beclamped together by the usual conventional flask C clamp. Each of theflask drag portions 3, 4, 5, 6, I and cope portions 8, e, H], H and i2,including the mold end closing portions 2, have at their ends anoutwardly extending semicircular or circular flange through whichextends from end tov end of the flask l bolts t5, with nuts I6 screwthreaded thereon at each of their ends whereby the several portions ofthe flask assembly are drawn into engagement with each other and asassembled are mounted rotatably on rails H in transversely spaced apartand parallel relation toeach other.

Mounted on the top of each cope portion 8, 9, 1,, II and i2, is a runnerand riser box I8 held between the outwardly extending semicircularflange at each end of each said cope portion and having thereinrefractory runner basin l'9- which extends to the higher-portions of themold cavity gate hole 20; and another compartment 21 having refractoryfeeder head member 22 therein with feedi sprue hole 23 extendingtherefrom to the mold cavity designated by numeral 24 in Figures '1; 3,lil, and conforms in shape to that of the portionof' the crank shaft tobe cast therein, which may be any portion of its length included in anyof the flask portions 3, 4, 5, 6,, l, 8; 9, H], ljl, I'Z; Numeral 25designates the, mold material of each of said portions; the, moldmaterial in the mold closing portion 21 which has cavity 26 providing a,shrinkage chamber with the, metal therein preventing piping of thecasting,

Numeral 2T refers to a portion of the crank shaft pattern extendingbetween the lines I and II in Figure 1 of the drawing, which, when thetwo portions of the mold and the flask portions are assembled, form themold cavity of a section of the mold in which to cast a portion of acrank shaft. With each section 3, l, 5, 6, l and 8, 9, Ni, ii and i 2,and portions 2 fastened together through tie bolts iii, the moldsections form a continuous elongated cylindrical mold with a continuousmold cavity longitudinally thereof.

Each cylindrical section of the mold, consisting of two semicylindricalportions which when assembled, forms a cylindrical portion havingannular flanges 29 at each end supported by the rails I7, and whenassembled, comprises the complete mold, as shown in Figures 4 and 5, andby virtue of the tie bolts 15, extending through equally spaced apartholes of the annular flanges 29, each section can be fastened to anadjacent section in such position annularly as to produce a crank shafthaving any desired angular spacing with its ends closed by portions 2.

In Figures 9 and 10, are shown a longitudinal half portion of a crankshaft pattern mounted on a pattern plate for forming the cope portion ofone of the mold sections having upwardly extending back 3! closing theflask portion at its ends with ledge 32 engaged by wedge 33 and as shownin Figure 9 as holding feeder hole forming member 34 in place while themold in one of the portions of the mold is being formed and extendingthrough the top of one of the flask portions 8, 9, Ni, ii, l2, with itssmaller end extending to and into pocket 34' of the pattern, the dragportions 3, l, 5, 6 and l, have no feeder or gate holes. The patternplate is provided with upwardly extending pins 35 extending throughholes 36 of the flanges l3, M of the flask portions, whereby the flaskportions are held against displacement on the pattern plate while beingfilled with molding sand or material and the required spacing of thesections to form the complete mold assembly shown in Figures 4 and 5.

It will be noted that the parting line between the cope and drag flasksmay be formed at any angle relative to the sprue opening. With the sprueopening located substantially vertically the parting line may be at anyangle thereto to give the proper angle to the offset crank arm of theresultant crank shaft. Thus the cranks may be cast at any desired angleand when a crank is to be located vertically in the completed mold thenthe sprue opening must be located slightly to one side of verticalcenter. The cranks of the crank shaft may be cast at any angle aroundthe axis of the shaft as for instance the various angles as shown inFigure 2 of the drawings.

When about to carry out my present method of producing crank shafts, Iprovide a plurality of similar semicylindrical flask portions eachhaving an outwardly extending flange at the sides with a plurality ofbolt holes extending therethrough and a semiannular outwardly extendingflange at each end with a plurality of equally spaced apart bolt holesextending therethrough and a pair of mold closing ends each having anoutwardly extending flange with bolt holes extending therethrough inequally spaced apart relation to each other and to the bolt holesextending through the semiannular flanges of the semicylindrical flaskportions. Having provided the flask and mold ends, I provide a patternof a portion of the crank shaft which, forv producing a crank shaft asshown in Figure 1, would require one pattern from which six similar moldportions would be made each two of which when turned over end to endwould comprise a cylindrical mold section to be joined to anothersimilar mold section by the tie bolts I5 extending through the properholes extending through the outwardly extending semi-annular flanges atthe ends of each section for the angular crank throw desired. Onesection of the mold having a mold cavity adapted to have cast thereinthe portion of the crank shaft extending from line I to the annularcoupling flange at the end of the crank shaft as shown in Figure 1 withthe flange itlself cast within the cavity 26 of the mold closing endportion. Prior to joining the several mold ctions together, all holesextending from the mold cavity in the drag portions of the mold areclosed by packing sand therein, and subsequent to assembling of the moldsections on the rails H, the pouring basin in the runner boss member 18and the head basin of the sprue hole 23 is formed. There being one spruehole and one runner basin on each mold section when casting large crankshafts for which the present method is particularly suitable. Themultiplicity of runner boxes and feeder extending therefrom preventsshort seams in the casting and the feeder sprues permit escape of frothfrom the top of the molten metal of the casting and provides moltenmetal for feeding back into the casting to compensate for shrinkagedownward of the molten metal as it solidifies in the casting and whichby reason of the casting consisting of an irregular shape and of steelis considerable which may be as great as one-quarter of an inch andmore.

While I have shown and described and illustrated my present invention asemployed in producin crank shafts, it should be understood the methodand apparatus can be employed for the casting of other irregular shapedshafts and bars; further, that short bolts extending through the annularflanges at each end of the flask sections can be employed to fasten theadjacent flask sections together to form a continuous mold in which toproduce the desired casting.

Having described my present invention, the rights thereto I desire tosecure by Letters Patent are:

A crank shaft mold comprising, a plurality of open end cylindrical moldboxes secured together end to end, each mold box comprising a pair ofsemi-cylindrical flasks secured together, a sand mold and mold cavitywithin each mold box for forming one crank arm and the adjacentcylindrical portions of the crank shaft, the part ng line between theflasks being coincident with the angle of the crank arm and a sprueopening {axtending from the exterior of each mold box to the mold cavitytherein, the mold boxes being secured together so that the parting lineof the flasks lie in different angular planes with respect shaft.

to the central axis of the crank IVAN OLSEN.

' REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

